Support adding additional signals in the Signal constructor

[laugengebaeck]

Currently, you can only add additional signals (like Zs3) to a Signal by directly writing to the attribute, not by specifying them in the constructor. The constructor only sets an empty list for additional_signals. It would be nice to also handle that in the constructor.

See

yaramo/yaramo/signal.py

Line 155 in f394106

self.additional_signals: list[AdditionalSignal] = []

(Note: I can implement this myself once I have time)